Psoriasis

Psoriasis is a chronic disease in which the immune system becomes overactive, causing skin cells to multiply too quickly. Patches of skin become scaly and inflamed, most often on the scalp, elbows, or knees, but other parts of the body can be affected as well.

What is the main cause of psoriasis?

The cause of psoriasis isn't fully understood. It's thought to be an immune system problem where infection-fighting cells attack healthy skin cells by mistake.